Language is the basic tool for the teacher's work. Meanwhile, pedagogues often forget that this tool becomes obsolete, just like the knowledge they pass on in class. The article is an attempt to draw attention to the need to learn the language spoken by young people. Thanks to this, teachers can often understand the student's statement, and thus – take appropriate intervention. It is necessary to know everyday expressions, know what the abbreviations used in text messages mean, and above all be sensitive to phrases that may indicate pathological behaviour. The article contains a few examples of words whose meaning is worth knowing when working with young people.